Recently, various types of technology for implementing increase in the recording capacity of a magnetic disk drive (hereinafter also called HDD) which is an example of recording devices have been developed. One type of recording technology is called shingled write recording (SMR). The shingled write recording writes data to a magnetic disk by overlapping the recording track on a part of a track adjacent to the recording track. The tracks per inch (TPI) can be increased by adopting the shingled write recording.
In addition, a host aware/managed-type magnetic disk drive issues a write request signal so as to allow a magnetic disk drive to efficiently write data to a magnetic disk with shingled write recording operations has been proposed.
When data is written in a track group (called a band) which is a recording unit of the shingled write recording and which includes a plurality of tracks, data held in an adjacent band is influenced by magnetic interference called adjacent track interference (ATI). For this reason, when data is repeatedly written to a particular band on the magnetic disk, the data in the adjacent band is repeatedly affected by the magnetic interference and may become unreadable (lost). In the host aware/managed-type magnetic disk drive, data may be repeatedly written in a particular band.
To prevent the data from being unreadable (data loss), the magnetic disk drive has a (data refresh) function of voluntarily rewriting the data in the band. In the host aware/managed-type magnetic disk drive, data refresh may occur in a plurality of bands at once. Therefore, a performance of response in the magnetic disk drive to the request from the host may be deteriorated.